Hmm, it never worked well for me. People just get more entrenched and resentful? What I have found works is to try and find some common ground and build up some level of mutual respect from there.
For example, I also grew up in a cult of southern baptist flavour. I've seen some fucked up shit too. Where the cult was a majority, they did a lot of shunning and shaming and that sucked. I just don't think that's right.
You cannot find common ground with someone whose world view is you are a subhuman worthy of slavery or death.
And why should we make the effort when they make none?
Rule of the biggest tribe with the biggest sticks still applies even today I suppose.
But one day...religion is dying out, slowly but surely. I can't wait for the day when the religious have to face what they dished out. I have no patience to teach people that who I am isn't worthy of death or admonishment again and again.